xref: /openbmc/u-boot/lib/string.c (revision dcac25a0)
1 /*
2  *  linux/lib/string.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  */
6 
7 /*
8  * stupid library routines.. The optimized versions should generally be found
9  * as inline code in <asm-xx/string.h>
10  *
11  * These are buggy as well..
12  *
13  * * Fri Jun 25 1999, Ingo Oeser <ioe@informatik.tu-chemnitz.de>
14  * -  Added strsep() which will replace strtok() soon (because strsep() is
15  *    reentrant and should be faster). Use only strsep() in new code, please.
16  */
17 
18 #include <linux/types.h>
19 #include <linux/string.h>
20 #include <linux/ctype.h>
21 #include <malloc.h>
22 
23 
24 #if 0 /* not used - was: #ifndef __HAVE_ARCH_STRNICMP */
25 /**
26  * strnicmp - Case insensitive, length-limited string comparison
27  * @s1: One string
28  * @s2: The other string
29  * @len: the maximum number of characters to compare
30  */
31 int strnicmp(const char *s1, const char *s2, size_t len)
32 {
33 	/* Yes, Virginia, it had better be unsigned */
34 	unsigned char c1, c2;
35 
36 	c1 = 0;	c2 = 0;
37 	if (len) {
38 		do {
39 			c1 = *s1; c2 = *s2;
40 			s1++; s2++;
41 			if (!c1)
42 				break;
43 			if (!c2)
44 				break;
45 			if (c1 == c2)
46 				continue;
47 			c1 = tolower(c1);
48 			c2 = tolower(c2);
49 			if (c1 != c2)
50 				break;
51 		} while (--len);
52 	}
53 	return (int)c1 - (int)c2;
54 }
55 #endif
56 
57 char * ___strtok;
58 
59 #ifndef __HAVE_ARCH_STRCPY
60 /**
61  * strcpy - Copy a %NUL terminated string
62  * @dest: Where to copy the string to
63  * @src: Where to copy the string from
64  */
65 char * strcpy(char * dest,const char *src)
66 {
67 	char *tmp = dest;
68 
69 	while ((*dest++ = *src++) != '\0')
70 		/* nothing */;
71 	return tmp;
72 }
73 #endif
74 
75 #ifndef __HAVE_ARCH_STRNCPY
76 /**
77  * strncpy - Copy a length-limited, %NUL-terminated string
78  * @dest: Where to copy the string to
79  * @src: Where to copy the string from
80  * @count: The maximum number of bytes to copy
81  *
82  * Note that unlike userspace strncpy, this does not %NUL-pad the buffer.
83  * However, the result is not %NUL-terminated if the source exceeds
84  * @count bytes.
85  */
86 char * strncpy(char * dest,const char *src,size_t count)
87 {
88 	char *tmp = dest;
89 
90 	while (count-- && (*dest++ = *src++) != '\0')
91 		/* nothing */;
92 
93 	return tmp;
94 }
95 #endif
96 
97 #ifndef __HAVE_ARCH_STRCAT
98 /**
99  * strcat - Append one %NUL-terminated string to another
100  * @dest: The string to be appended to
101  * @src: The string to append to it
102  */
103 char * strcat(char * dest, const char * src)
104 {
105 	char *tmp = dest;
106 
107 	while (*dest)
108 		dest++;
109 	while ((*dest++ = *src++) != '\0')
110 		;
111 
112 	return tmp;
113 }
114 #endif
115 
116 #ifndef __HAVE_ARCH_STRNCAT
117 /**
118  * strncat - Append a length-limited, %NUL-terminated string to another
119  * @dest: The string to be appended to
120  * @src: The string to append to it
121  * @count: The maximum numbers of bytes to copy
122  *
123  * Note that in contrast to strncpy, strncat ensures the result is
124  * terminated.
125  */
126 char * strncat(char *dest, const char *src, size_t count)
127 {
128 	char *tmp = dest;
129 
130 	if (count) {
131 		while (*dest)
132 			dest++;
133 		while ((*dest++ = *src++)) {
134 			if (--count == 0) {
135 				*dest = '\0';
136 				break;
137 			}
138 		}
139 	}
140 
141 	return tmp;
142 }
143 #endif
144 
145 #ifndef __HAVE_ARCH_STRCMP
146 /**
147  * strcmp - Compare two strings
148  * @cs: One string
149  * @ct: Another string
150  */
151 int strcmp(const char * cs,const char * ct)
152 {
153 	register signed char __res;
154 
155 	while (1) {
156 		if ((__res = *cs - *ct++) != 0 || !*cs++)
157 			break;
158 	}
159 
160 	return __res;
161 }
162 #endif
163 
164 #ifndef __HAVE_ARCH_STRNCMP
165 /**
166  * strncmp - Compare two length-limited strings
167  * @cs: One string
168  * @ct: Another string
169  * @count: The maximum number of bytes to compare
170  */
171 int strncmp(const char * cs,const char * ct,size_t count)
172 {
173 	register signed char __res = 0;
174 
175 	while (count) {
176 		if ((__res = *cs - *ct++) != 0 || !*cs++)
177 			break;
178 		count--;
179 	}
180 
181 	return __res;
182 }
183 #endif
184 
185 #ifndef __HAVE_ARCH_STRCHR
186 /**
187  * strchr - Find the first occurrence of a character in a string
188  * @s: The string to be searched
189  * @c: The character to search for
190  */
191 char * strchr(const char * s, int c)
192 {
193 	for(; *s != (char) c; ++s)
194 		if (*s == '\0')
195 			return NULL;
196 	return (char *) s;
197 }
198 #endif
199 
200 #ifndef __HAVE_ARCH_STRRCHR
201 /**
202  * strrchr - Find the last occurrence of a character in a string
203  * @s: The string to be searched
204  * @c: The character to search for
205  */
206 char * strrchr(const char * s, int c)
207 {
208        const char *p = s + strlen(s);
209        do {
210 	   if (*p == (char)c)
211 	       return (char *)p;
212        } while (--p >= s);
213        return NULL;
214 }
215 #endif
216 
217 #ifndef __HAVE_ARCH_STRLEN
218 /**
219  * strlen - Find the length of a string
220  * @s: The string to be sized
221  */
222 size_t strlen(const char * s)
223 {
224 	const char *sc;
225 
226 	for (sc = s; *sc != '\0'; ++sc)
227 		/* nothing */;
228 	return sc - s;
229 }
230 #endif
231 
232 #ifndef __HAVE_ARCH_STRNLEN
233 /**
234  * strnlen - Find the length of a length-limited string
235  * @s: The string to be sized
236  * @count: The maximum number of bytes to search
237  */
238 size_t strnlen(const char * s, size_t count)
239 {
240 	const char *sc;
241 
242 	for (sc = s; count-- && *sc != '\0'; ++sc)
243 		/* nothing */;
244 	return sc - s;
245 }
246 #endif
247 
248 #ifndef __HAVE_ARCH_STRDUP
249 char * strdup(const char *s)
250 {
251 	char *new;
252 
253 	if ((s == NULL)	||
254 	    ((new = malloc (strlen(s) + 1)) == NULL) ) {
255 		return NULL;
256 	}
257 
258 	strcpy (new, s);
259 	return new;
260 }
261 #endif
262 
263 #ifndef __HAVE_ARCH_STRSPN
264 /**
265  * strspn - Calculate the length of the initial substring of @s which only
266  *	contain letters in @accept
267  * @s: The string to be searched
268  * @accept: The string to search for
269  */
270 size_t strspn(const char *s, const char *accept)
271 {
272 	const char *p;
273 	const char *a;
274 	size_t count = 0;
275 
276 	for (p = s; *p != '\0'; ++p) {
277 		for (a = accept; *a != '\0'; ++a) {
278 			if (*p == *a)
279 				break;
280 		}
281 		if (*a == '\0')
282 			return count;
283 		++count;
284 	}
285 
286 	return count;
287 }
288 #endif
289 
290 #ifndef __HAVE_ARCH_STRPBRK
291 /**
292  * strpbrk - Find the first occurrence of a set of characters
293  * @cs: The string to be searched
294  * @ct: The characters to search for
295  */
296 char * strpbrk(const char * cs,const char * ct)
297 {
298 	const char *sc1,*sc2;
299 
300 	for( sc1 = cs; *sc1 != '\0'; ++sc1) {
301 		for( sc2 = ct; *sc2 != '\0'; ++sc2) {
302 			if (*sc1 == *sc2)
303 				return (char *) sc1;
304 		}
305 	}
306 	return NULL;
307 }
308 #endif
309 
310 #ifndef __HAVE_ARCH_STRTOK
311 /**
312  * strtok - Split a string into tokens
313  * @s: The string to be searched
314  * @ct: The characters to search for
315  *
316  * WARNING: strtok is deprecated, use strsep instead.
317  */
318 char * strtok(char * s,const char * ct)
319 {
320 	char *sbegin, *send;
321 
322 	sbegin  = s ? s : ___strtok;
323 	if (!sbegin) {
324 		return NULL;
325 	}
326 	sbegin += strspn(sbegin,ct);
327 	if (*sbegin == '\0') {
328 		___strtok = NULL;
329 		return( NULL );
330 	}
331 	send = strpbrk( sbegin, ct);
332 	if (send && *send != '\0')
333 		*send++ = '\0';
334 	___strtok = send;
335 	return (sbegin);
336 }
337 #endif
338 
339 #ifndef __HAVE_ARCH_STRSEP
340 /**
341  * strsep - Split a string into tokens
342  * @s: The string to be searched
343  * @ct: The characters to search for
344  *
345  * strsep() updates @s to point after the token, ready for the next call.
346  *
347  * It returns empty tokens, too, behaving exactly like the libc function
348  * of that name. In fact, it was stolen from glibc2 and de-fancy-fied.
349  * Same semantics, slimmer shape. ;)
350  */
351 char * strsep(char **s, const char *ct)
352 {
353 	char *sbegin = *s, *end;
354 
355 	if (sbegin == NULL)
356 		return NULL;
357 
358 	end = strpbrk(sbegin, ct);
359 	if (end)
360 		*end++ = '\0';
361 	*s = end;
362 
363 	return sbegin;
364 }
365 #endif
366 
367 #ifndef __HAVE_ARCH_STRSWAB
368 /**
369  * strswab - swap adjacent even and odd bytes in %NUL-terminated string
370  * s: address of the string
371  *
372  * returns the address of the swapped string or NULL on error. If
373  * string length is odd, last byte is untouched.
374  */
375 char *strswab(const char *s)
376 {
377 	char *p, *q;
378 
379 	if ((NULL == s) || ('\0' == *s)) {
380 		return (NULL);
381 	}
382 
383 	for (p=(char *)s, q=p+1; (*p != '\0') && (*q != '\0'); p+=2, q+=2) {
384 		char  tmp;
385 
386 		tmp = *p;
387 		*p  = *q;
388 		*q  = tmp;
389 	}
390 
391 	return (char *) s;
392 }
393 #endif
394 
395 #ifndef __HAVE_ARCH_MEMSET
396 /**
397  * memset - Fill a region of memory with the given value
398  * @s: Pointer to the start of the area.
399  * @c: The byte to fill the area with
400  * @count: The size of the area.
401  *
402  * Do not use memset() to access IO space, use memset_io() instead.
403  */
404 void * memset(void * s,int c,size_t count)
405 {
406 	unsigned long *sl = (unsigned long *) s;
407 	unsigned long cl = 0;
408 	char *s8;
409 	int i;
410 
411 	/* do it one word at a time (32 bits or 64 bits) while possible */
412 	if ( ((ulong)s & (sizeof(*sl) - 1)) == 0) {
413 		for (i = 0; i < sizeof(*sl); i++) {
414 			cl <<= 8;
415 			cl |= c & 0xff;
416 		}
417 		while (count >= sizeof(*sl)) {
418 			*sl++ = cl;
419 			count -= sizeof(*sl);
420 		}
421 	}
422 	/* fill 8 bits at a time */
423 	s8 = (char *)sl;
424 	while (count--)
425 		*s8++ = c;
426 
427 	return s;
428 }
429 #endif
430 
431 #ifndef __HAVE_ARCH_BCOPY
432 /**
433  * bcopy - Copy one area of memory to another
434  * @src: Where to copy from
435  * @dest: Where to copy to
436  * @count: The size of the area.
437  *
438  * Note that this is the same as memcpy(), with the arguments reversed.
439  * memcpy() is the standard, bcopy() is a legacy BSD function.
440  *
441  * You should not use this function to access IO space, use memcpy_toio()
442  * or memcpy_fromio() instead.
443  */
444 char * bcopy(const char * src, char * dest, int count)
445 {
446 	char *tmp = dest;
447 
448 	while (count--)
449 		*tmp++ = *src++;
450 
451 	return dest;
452 }
453 #endif
454 
455 #ifndef __HAVE_ARCH_MEMCPY
456 /**
457  * memcpy - Copy one area of memory to another
458  * @dest: Where to copy to
459  * @src: Where to copy from
460  * @count: The size of the area.
461  *
462  * You should not use this function to access IO space, use memcpy_toio()
463  * or memcpy_fromio() instead.
464  */
465 void * memcpy(void *dest, const void *src, size_t count)
466 {
467 	unsigned long *dl = (unsigned long *)dest, *sl = (unsigned long *)src;
468 	char *d8, *s8;
469 
470 	if (src == dest)
471 		return dest;
472 
473 	/* while all data is aligned (common case), copy a word at a time */
474 	if ( (((ulong)dest | (ulong)src) & (sizeof(*dl) - 1)) == 0) {
475 		while (count >= sizeof(*dl)) {
476 			*dl++ = *sl++;
477 			count -= sizeof(*dl);
478 		}
479 	}
480 	/* copy the reset one byte at a time */
481 	d8 = (char *)dl;
482 	s8 = (char *)sl;
483 	while (count--)
484 		*d8++ = *s8++;
485 
486 	return dest;
487 }
488 #endif
489 
490 #ifndef __HAVE_ARCH_MEMMOVE
491 /**
492  * memmove - Copy one area of memory to another
493  * @dest: Where to copy to
494  * @src: Where to copy from
495  * @count: The size of the area.
496  *
497  * Unlike memcpy(), memmove() copes with overlapping areas.
498  */
499 void * memmove(void * dest,const void *src,size_t count)
500 {
501 	char *tmp, *s;
502 
503 	if (src == dest)
504 		return dest;
505 
506 	if (dest <= src) {
507 		tmp = (char *) dest;
508 		s = (char *) src;
509 		while (count--)
510 			*tmp++ = *s++;
511 		}
512 	else {
513 		tmp = (char *) dest + count;
514 		s = (char *) src + count;
515 		while (count--)
516 			*--tmp = *--s;
517 		}
518 
519 	return dest;
520 }
521 #endif
522 
523 #ifndef __HAVE_ARCH_MEMCMP
524 /**
525  * memcmp - Compare two areas of memory
526  * @cs: One area of memory
527  * @ct: Another area of memory
528  * @count: The size of the area.
529  */
530 int memcmp(const void * cs,const void * ct,size_t count)
531 {
532 	const unsigned char *su1, *su2;
533 	int res = 0;
534 
535 	for( su1 = cs, su2 = ct; 0 < count; ++su1, ++su2, count--)
536 		if ((res = *su1 - *su2) != 0)
537 			break;
538 	return res;
539 }
540 #endif
541 
542 #ifndef __HAVE_ARCH_MEMSCAN
543 /**
544  * memscan - Find a character in an area of memory.
545  * @addr: The memory area
546  * @c: The byte to search for
547  * @size: The size of the area.
548  *
549  * returns the address of the first occurrence of @c, or 1 byte past
550  * the area if @c is not found
551  */
552 void * memscan(void * addr, int c, size_t size)
553 {
554 	unsigned char * p = (unsigned char *) addr;
555 
556 	while (size) {
557 		if (*p == c)
558 			return (void *) p;
559 		p++;
560 		size--;
561 	}
562 	return (void *) p;
563 }
564 #endif
565 
566 #ifndef __HAVE_ARCH_STRSTR
567 /**
568  * strstr - Find the first substring in a %NUL terminated string
569  * @s1: The string to be searched
570  * @s2: The string to search for
571  */
572 char * strstr(const char * s1,const char * s2)
573 {
574 	int l1, l2;
575 
576 	l2 = strlen(s2);
577 	if (!l2)
578 		return (char *) s1;
579 	l1 = strlen(s1);
580 	while (l1 >= l2) {
581 		l1--;
582 		if (!memcmp(s1,s2,l2))
583 			return (char *) s1;
584 		s1++;
585 	}
586 	return NULL;
587 }
588 #endif
589 
590 #ifndef __HAVE_ARCH_MEMCHR
591 /**
592  * memchr - Find a character in an area of memory.
593  * @s: The memory area
594  * @c: The byte to search for
595  * @n: The size of the area.
596  *
597  * returns the address of the first occurrence of @c, or %NULL
598  * if @c is not found
599  */
600 void *memchr(const void *s, int c, size_t n)
601 {
602 	const unsigned char *p = s;
603 	while (n-- != 0) {
604 		if ((unsigned char)c == *p++) {
605 			return (void *)(p-1);
606 		}
607 	}
608 	return NULL;
609 }
610 
611 #endif
612